Refs Tokutek/ft-index#28 attach gdb to the running process and extract information on fatal signal.
(cherry picked from commit 0f02058727fa7ae7888ea2daf493fb178896ed16)
refs Tokutek/ft-index#28 fix help file result test
(cherry picked from commit 7e2ab0c601a5bc080fb8576ebbd1204a343404b5)